On the French Riviera, Christopher Tracy and his brother, “Tricky,” divide their time between being musicians at a posh hotel and pursuing wealthy women. One evening, a lady named Mrs. Wellington plies Christopher with drinks as he plays piano. They exchange longing looks and later, they make love in her hotel room. Mrs. Wellington lives off of a $3 million divorce settlement but Christopher has his sights set higher. When the newspaper society pages announce that shipping heiress Mary Sharon is celebrating her twenty-first birthday, Christopher wrangles an invitation. All of France’s "glitterati" attend Mary’s birthday party. Wearing only a bath towel, Mary exposes her nude body and asks her guests if they like her birthday suit. After she accompanies the band from behind a drum kit, Mary notices Christopher and decides that he is a hustler who has crashed her party. When he sneaks into her bedroom, she kicks him out. As he leaves, he shows her birthday invitations that were sent to him and Tricky. Mrs. Wellington is also a party guest and Christopher goes home with her. The next day, Mary Sharon is intrigued by Christopher, finds him and hurls insults as he plays for the lunch crowd in the hotel dining room. Tricky charms Mary as they dance, and she invites the brothers to join her the following evening. Christopher cuts in and dances with Mary on an outdoor patio. They engage in a verbal sparring match to uncover each other’s motives that ends poorly, and Christopher returns to work. Later, the brothers party with Mary at an elegant restaurant. Christopher and Tricky take over the dance floor with a large audio cassette player “boom box,” and gets the crowd swinging to roll and roll music. The maître d’ summons Mary’s father, who demands that she leave, and orders his associates to do background checks on the Tracy brothers. Meanwhile, Mary has fallen for the Tracys' charm and sense of fun. When Mr. Sharon gives his daughter a generous bundle of cash as an apology for missing her birthday party. Separating her from her friends, she asks Christopher and Tricky to help her spend it. They buy expensive clothes, a sports car, and Rolex watches. Although Tricky considers Mary another one of their business deals, Christopher contemplates quitting show business to be with her. At night, Christopher arranges to meet Mary at a deserted racetrack. After a mock drag race, Mary and Christopher make love while Tricky waits for Christopher and Mary to appear at a hip nightclub. When Mary teases Christopher about his poor spelling, he criticizes her for being a poor little rich girl and threatens to call her father to come get her. Christopher does call Mr. Sharon, boasts that he and Mary are in love, and Mr. Sharon will never break them apart. Mary hangs up the phone, and insists that her father has the power to destroy Christopher. In the morning, Mary and her father fight about her sordid social life. He is furious that she is sabotaging her engagement to Jonathan Donahue, a suitor who is a member of a wealthy family. At their apartment, Tricky is angry that Christopher has deviated from their usual arrangement to become Mary’s lover, and left him waiting at the nightclub. When Tricky insists that Mary will use him and leave him, Christopher stalks off and finds Mary in the lobby. She suggests they run away for a couple of hours. They make love in a grotto along the cliffs. In a drunken rage, Tricky confronts his brother and Mary when they return. He wants to know if he will still get his thirty percent cut if Christopher marries Mary. Her mood turns icy and she retreats into her father’s chauffeur-driven Rolls Royce, which was following the lovers. Christopher drinks to drown his pain, and visits Mrs. Wellington, who hands him a $100,000 check from Mr. Sharon. The money is his if he promises never to see Mary again. When he refuses, she tells him Mary and her mother plan to leave for New York on their private plane. Christopher kidnaps Mary at the airport, and seduces her in the back seat of his car as they try to decide if they still have a relationship. Mr. Sharon’s associates ambush Tricky but he escapes. At the grotto, Mary reads romantic poetry that Christopher has written as Tricky warns his brother that Mr. Sharon and his men are scouring the harbor. As Christopher docks his boat near the grotto, Mr. Sharon’s men shoot him dead. Although she mourns for Christopher, Mary buys a luxury building in Miami, Florida, and hires Tricky to be the manager. She misses Christopher, but plans to visit Tricky in a few months to check on their investment.